WAR IN IRAQ - COALITION HEADQUARTERS TARGETED

Some Of Those Slain Might Have Been Americans, But Authorities Had Not Been Able To Easily Identify Many Of The Bodies.

BAGHDAD, Iraq -- A blast that killed at least 20 people Sunday -- possibly including two U.S. citizens -- outside the U.S.-led coalition's headquarters was set off by a suicide bomber in a truck laden with 1,000 pounds of Soviet-made plastic explosives, authorities said.

The bombing dimmed the hopes of those who expected last month's capture of Saddam Hussein to reduce the number of deadly attacks.

It also underscored the challenges faced by the United States as it attempts to persuade other countries, foreign investors and private contractors to join the reconstruction of Iraq.

U.S. officials said they were still trying to determine whether Americans were among the casualties.

"We have indications that some of those killed were American citizens," said Brig Gen. Mark Kimmitt, a military spokesman. "Many of the bodies, as you might imagine, because of the nature of the crime, we have not been able to determine their nationality nor their names."

A military official said early reports of two American fatalities were based on scraps of clothing found on the scene that resembled uniforms worn by U.S. contractors.

U.S. troops and American workers here have rarely been killed in suicide car bombings. Previous attacks have taken the heaviest toll on Iraqi civilians and police officers.

Officials think the suicide bomber drove a small pickup or sport utility vehicle within 15 yards of a military checkpoint at the front gate of Saddam's former Republican Palace.

"[The bomber] may have inadvertently triggered it himself or he may have felt that because of the security he could not penetrate the checkpoint and decided to [detonate]," said Col. Ralph Baker, commander of the 2nd Brigade of the 1st Armored Division, which provides security for the so-called "green zone."

Most of the fatalities occurred in the busy intersection outside the complex, where more than a dozen cars and a city bus were destroyed, Baker said.

At least 60 were wounded, including many Iraqi workers waiting to start their jobs inside the green zone.

"This act of terrorism will not deter us from moving forward and building a stable, democratic and free Iraq," said Hamid Kafai, a spokesman for the U.S.-appointed Iraqi Governing Council, which is based inside the complex. "This terrorist act is another stain on Saddam's regime and his terrorist allies, be they local or foreign."

By Sunday afternoon, U.S. investigators were sifting through the debris as workers in protective gloves and masks carried out victims in body bags.

The attack frightened many Iraqi workers who take considerable risks when they show up for work within the green zone.

Every day, when he walks across the Republic Bridge to wash cars, said Jassim Ahmed, "my heart shrinks."

After the bombing, which he witnessed as he approached the entrance Sunday, he swore he would never return. "If they tell me that the Kaaba itself is there, I will not go back," said Ahmed, referring to the stone cube that is the holiest object in Islam, the destination of hajj pilgrims in Mecca and in whose direction Muslims must pray.

Abbass Al-Kinani has been the envy of his friends for seven months because he worked in the American gym in the green zone, made $5 a day, got to share meals with his supervisors at the soldiers' canteen and pocketed gifts from the United States including a portable CD player.

Seven of his co-workers were injured in the explosion.

"Tomorrow I'll go in and return my badge," the 21-year-old said as he fingered his identification tag Sunday afternoon. "No more."

Several workers said they did not have a choice.

"We have to work with the Americans," said Abbas Kadhum, 27, a resident of the Sadr City slum. "They have a system: Either you work with them or you starve."

Kadhum, who makes $7 a day filling sandbags in the zone, tried to dismiss the attack. "We are getting used to explosions," he said. "We were raised with explosions, all these wars."

His brother acknowledged the risks. "If we quit working, we'll die of hunger," he said. "We're intimidated; we're afraid, but we have to keep working."

At dusk, the blast scene was ringed with Iraqis desperate for news of relatives who worked in the zone. "I saw my husband on television, just before the explosion," sobbed one woman.

The blast flared tempers throughout the capital, reigniting resentment against the Americans and neighboring Arab nations, which some Iraqis think are sending foreign fighters to destabilize their country. The U.S. military shut down the Republican Bridge and other major thoroughfares, spurring huge traffic jams across the city.

After reviewing the carnage Sunday morning, Lt. Gen. Ahmed Kadhem, Baghdad's chief of police, was mobbed by scores of angry Iraqis, accusing him of failing to stop the violence.

"These are not Iraqis who are doing this," one man shouted. "They are Egyptians and Jordanians and Syrians and Kuwaitis. We will remember and take our revenge."